i850 HIS SCIENTIFIC WORK 6, 



Then as to Salpa, whose mode of generation has always been 

 so great a bone of contention, I have a long series of observa- 

 tions and drawings which I have verified over and over again, 

 and which, if correct, must give rise to quite a new view of the 

 matter. I may mention as an interesting fact that in these 

 animals so low in the scale I have found a placental circulation, 

 rudimentary indeed, but nevertheless a perfect model on a small 

 scale of that which takes place in the mammalia. 



6. I have the materials for a monograph upon the Acalephae 

 and Hydrostatic Acalephae. I have examined very carefully more 

 than forty genera of these animals — many of them very rare, and 

 some quite new. But I paid comparatively little attention to the 

 collection of new species, caring rather to come to some clear 

 and definite idea as to the structure of those which had indeed 

 been long known, but very little understood. Unfortunately for 

 science, but fortunately for me, this method appears to have been 

 somewhat novel with observers of these animals, and conse- 

 quently everywhere new and remarkable facts were to be had 

 for the picking up. 



It is not to be supposed that one could occupy one's self with 

 the animals for so long without coming to some conclusion as to 

 their systematic place, however subsidiary to observation such 

 considerations must always be regarded, and it seems to me 

 (although on such matters I can of course only speak with 

 the greatest hesitation) that just as the more minute and careful 

 observations made upon the old " Vermes " of Linnaeus neces- 

 sitated the breaking up of that class into several very distinct 

 classes, so more careful investigation requires the breaking up 

 of Cuvier's " Radiata " (which succeeded the "Vermes" as a 

 sort of zoological lumber-room) into several very distinct and 

 well-defined new classes, of which the Acalephae, Hydrostatic 

 Acalephae, actinoid and hydroid polypes, will form one. But I 

 fear that I am trespassing beyond the limits of a letter. I have 

 only wished to state what I have done in order that you may 

 judge concerning the propriety or impropriety of what I propose 

 to do. And I trust that you will not think that I am presuming 

 too much upon your kindness if I take the liberty of thus asking 

 your advice about my own affairs. In truth, I feel in a manner 

 responsible to you for the use of the appointment you procured 

 for me; and furthermore, Capt. Stanley's unfortunate decease 

 has left the interests of the ship in general and my own in par- 

 ticular without a representative. 



Can you inform me, then, what chance I should have either 



